1 //===---- MachO_arm64.cpp - JIT linker implementation for MachO/arm64 -----===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // MachO/arm64 jit-link implementation. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/ExecutionEngine/JITLink/MachO_arm64.h" 14 15 #include "MachOLinkGraphBuilder.h" 16 #include "PerGraphGOTAndPLTStubsBuilder.h" 17 18 #define DEBUG_TYPE "jitlink" 19 20 using namespace llvm; 21 using namespace llvm::jitlink; 22 using namespace llvm::jitlink::MachO_arm64_Edges; 23 24 namespace { 25 26 class MachOLinkGraphBuilder_arm64 : public MachOLinkGraphBuilder { 27 public: 28 MachOLinkGraphBuilder_arm64(const object::MachOObjectFile &Obj) 29 : MachOLinkGraphBuilder(Obj, Triple("arm64-apple-darwin"), 30 getMachOARM64RelocationKindName), 31 NumSymbols(Obj.getSymtabLoadCommand().nsyms) {} 32 33 private: 34 static Expected<MachOARM64RelocationKind> 35 getRelocationKind(const MachO::relocation_info &RI) { 36 switch (RI.r_type) { 37 case MachO::ARM64_RELOC_UNSIGNED: 38 if (!RI.r_pcrel) { 39 if (RI.r_length == 3) 40 return RI.r_extern ? Pointer64 : Pointer64Anon; 41 else if (RI.r_length == 2) 42 return Pointer32; 43 } 44 break; 45 case MachO::ARM64_RELOC_SUBTRACTOR: 46 // SUBTRACTOR must be non-pc-rel, extern, with length 2 or 3. 47 // Initially represent SUBTRACTOR relocations with 'Delta<W>'. 48 // They may be turned into NegDelta<W> by parsePairRelocation. 49 if (!RI.r_pcrel && RI.r_extern) { 50 if (RI.r_length == 2) 51 return Delta32; 52 else if (RI.r_length == 3) 53 return Delta64; 54 } 55 break; 56 case MachO::ARM64_RELOC_BRANCH26: 57 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 58 return Branch26; 59 break; 60 case MachO::ARM64_RELOC_PAGE21: 61 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 62 return Page21; 63 break; 64 case MachO::ARM64_RELOC_PAGEOFF12: 65 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 66 return PageOffset12; 67 break; 68 case MachO::ARM64_RELOC_GOT_LOAD_PAGE21: 69 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 70 return GOTPage21; 71 break; 72 case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12: 73 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 74 return GOTPageOffset12; 75 break; 76 case MachO::ARM64_RELOC_POINTER_TO_GOT: 77 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 78 return PointerToGOT; 79 break; 80 case MachO::ARM64_RELOC_ADDEND: 81 if (!RI.r_pcrel && !RI.r_extern && RI.r_length == 2) 82 return PairedAddend; 83 break; 84 } 85 86 return make_error<JITLinkError>( 87 "Unsupported arm64 relocation: address=" + 88 formatv("{0:x8}", RI.r_address) + 89 ", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) + 90 ", kind=" + formatv("{0:x1}", RI.r_type) + 91 ", pc_rel=" + (RI.r_pcrel ? "true" : "false") + 92 ", extern=" + (RI.r_extern ? "true" : "false") + 93 ", length=" + formatv("{0:d}", RI.r_length)); 94 } 95 96 using PairRelocInfo = 97 std::tuple<MachOARM64RelocationKind, Symbol *, uint64_t>; 98 99 // Parses paired SUBTRACTOR/UNSIGNED relocations and, on success, 100 // returns the edge kind and addend to be used. 101 Expected<PairRelocInfo> 102 parsePairRelocation(Block &BlockToFix, Edge::Kind SubtractorKind, 103 const MachO::relocation_info &SubRI, 104 JITTargetAddress FixupAddress, const char *FixupContent, 105 object::relocation_iterator &UnsignedRelItr, 106 object::relocation_iterator &RelEnd) { 107 using namespace support; 108 109 assert(((SubtractorKind == Delta32 && SubRI.r_length == 2) || 110 (SubtractorKind == Delta64 && SubRI.r_length == 3)) && 111 "Subtractor kind should match length"); 112 assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern"); 113 assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel"); 114 115 if (UnsignedRelItr == RelEnd) 116 return make_error<JITLinkError>("arm64 SUBTRACTOR without paired " 117 "UNSIGNED relocation"); 118 119 auto UnsignedRI = getRelocationInfo(UnsignedRelItr); 120 121 if (SubRI.r_address != UnsignedRI.r_address) 122 return make_error<JITLinkError>("arm64 SUBTRACTOR and paired UNSIGNED " 123 "point to different addresses"); 124 125 if (SubRI.r_length != UnsignedRI.r_length) 126 return make_error<JITLinkError>("length of arm64 SUBTRACTOR and paired " 127 "UNSIGNED reloc must match"); 128 129 Symbol *FromSymbol; 130 if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum)) 131 FromSymbol = FromSymbolOrErr->GraphSymbol; 132 else 133 return FromSymbolOrErr.takeError(); 134 135 // Read the current fixup value. 136 uint64_t FixupValue = 0; 137 if (SubRI.r_length == 3) 138 FixupValue = *(const little64_t *)FixupContent; 139 else 140 FixupValue = *(const little32_t *)FixupContent; 141 142 // Find 'ToSymbol' using symbol number or address, depending on whether the 143 // paired UNSIGNED relocation is extern. 144 Symbol *ToSymbol = nullptr; 145 if (UnsignedRI.r_extern) { 146 // Find target symbol by symbol index. 147 if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum)) 148 ToSymbol = ToSymbolOrErr->GraphSymbol; 149 else 150 return ToSymbolOrErr.takeError(); 151 } else { 152 auto ToSymbolSec = findSectionByIndex(UnsignedRI.r_symbolnum - 1); 153 if (!ToSymbolSec) 154 return ToSymbolSec.takeError(); 155 ToSymbol = getSymbolByAddress(ToSymbolSec->Address); 156 assert(ToSymbol && "No symbol for section"); 157 FixupValue -= ToSymbol->getAddress(); 158 } 159 160 MachOARM64RelocationKind DeltaKind; 161 Symbol *TargetSymbol; 162 uint64_t Addend; 163 if (&BlockToFix == &FromSymbol->getAddressable()) { 164 TargetSymbol = ToSymbol; 165 DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32; 166 Addend = FixupValue + (FixupAddress - FromSymbol->getAddress()); 167 // FIXME: handle extern 'from'. 168 } else if (&BlockToFix == &ToSymbol->getAddressable()) { 169 TargetSymbol = &*FromSymbol; 170 DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32; 171 Addend = FixupValue - (FixupAddress - ToSymbol->getAddress()); 172 } else { 173 // BlockToFix was neither FromSymbol nor ToSymbol. 174 return make_error<JITLinkError>("SUBTRACTOR relocation must fix up " 175 "either 'A' or 'B' (or a symbol in one " 176 "of their alt-entry groups)"); 177 } 178 179 return PairRelocInfo(DeltaKind, TargetSymbol, Addend); 180 } 181 182 Error addRelocations() override { 183 using namespace support; 184 auto &Obj = getObject(); 185 186 LLVM_DEBUG(dbgs() << "Processing relocations:\n"); 187 188 for (auto &S : Obj.sections()) { 189 190 JITTargetAddress SectionAddress = S.getAddress(); 191 192 // Skip relocations virtual sections. 193 if (S.isVirtual()) { 194 if (S.relocation_begin() != S.relocation_end()) 195 return make_error<JITLinkError>("Virtual section contains " 196 "relocations"); 197 continue; 198 } 199 200 // Skip relocations for debug symbols. 201 { 202 auto &NSec = 203 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl())); 204 if (!NSec.GraphSection) { 205 LLVM_DEBUG({ 206 dbgs() << " Skipping relocations for MachO section " 207 << NSec.SegName << "/" << NSec.SectName 208 << " which has no associated graph section\n"; 209 }); 210 continue; 211 } 212 } 213 214 for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end(); 215 RelItr != RelEnd; ++RelItr) { 216 217 MachO::relocation_info RI = getRelocationInfo(RelItr); 218 219 // Sanity check the relocation kind. 220 auto Kind = getRelocationKind(RI); 221 if (!Kind) 222 return Kind.takeError(); 223 224 // Find the address of the value to fix up. 225 JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address; 226 227 LLVM_DEBUG({ 228 auto &NSec = 229 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl())); 230 dbgs() << " " << NSec.SectName << " + " 231 << formatv("{0:x8}", RI.r_address) << ":\n"; 232 }); 233 234 // Find the block that the fixup points to. 235 Block *BlockToFix = nullptr; 236 { 237 auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress); 238 if (!SymbolToFixOrErr) 239 return SymbolToFixOrErr.takeError(); 240 BlockToFix = &SymbolToFixOrErr->getBlock(); 241 } 242 243 if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) > 244 BlockToFix->getAddress() + BlockToFix->getContent().size()) 245 return make_error<JITLinkError>( 246 "Relocation content extends past end of fixup block"); 247 248 // Get a pointer to the fixup content. 249 const char *FixupContent = BlockToFix->getContent().data() + 250 (FixupAddress - BlockToFix->getAddress()); 251 252 // The target symbol and addend will be populated by the switch below. 253 Symbol *TargetSymbol = nullptr; 254 uint64_t Addend = 0; 255 256 if (*Kind == PairedAddend) { 257 // If this is an Addend relocation then process it and move to the 258 // paired reloc. 259 260 Addend = SignExtend64(RI.r_symbolnum, 24); 261 262 if (RelItr == RelEnd) 263 return make_error<JITLinkError>("Unpaired Addend reloc at " + 264 formatv("{0:x16}", FixupAddress)); 265 ++RelItr; 266 RI = getRelocationInfo(RelItr); 267 268 Kind = getRelocationKind(RI); 269 if (!Kind) 270 return Kind.takeError(); 271 272 if (*Kind != Branch26 && *Kind != Page21 && *Kind != PageOffset12) 273 return make_error<JITLinkError>( 274 "Invalid relocation pair: Addend + " + 275 StringRef(getMachOARM64RelocationKindName(*Kind))); 276 277 LLVM_DEBUG({ 278 dbgs() << " Addend: value = " << formatv("{0:x6}", Addend) 279 << ", pair is " << getMachOARM64RelocationKindName(*Kind) 280 << "\n"; 281 }); 282 283 // Find the address of the value to fix up. 284 JITTargetAddress PairedFixupAddress = 285 SectionAddress + (uint32_t)RI.r_address; 286 if (PairedFixupAddress != FixupAddress) 287 return make_error<JITLinkError>("Paired relocation points at " 288 "different target"); 289 } 290 291 switch (*Kind) { 292 case Branch26: { 293 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 294 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 295 else 296 return TargetSymbolOrErr.takeError(); 297 uint32_t Instr = *(const ulittle32_t *)FixupContent; 298 if ((Instr & 0x7fffffff) != 0x14000000) 299 return make_error<JITLinkError>("BRANCH26 target is not a B or BL " 300 "instruction with a zero addend"); 301 break; 302 } 303 case Pointer32: 304 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 305 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 306 else 307 return TargetSymbolOrErr.takeError(); 308 Addend = *(const ulittle32_t *)FixupContent; 309 break; 310 case Pointer64: 311 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 312 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 313 else 314 return TargetSymbolOrErr.takeError(); 315 Addend = *(const ulittle64_t *)FixupContent; 316 break; 317 case Pointer64Anon: { 318 JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent; 319 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress)) 320 TargetSymbol = &*TargetSymbolOrErr; 321 else 322 return TargetSymbolOrErr.takeError(); 323 Addend = TargetAddress - TargetSymbol->getAddress(); 324 break; 325 } 326 case Page21: 327 case GOTPage21: { 328 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 329 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 330 else 331 return TargetSymbolOrErr.takeError(); 332 uint32_t Instr = *(const ulittle32_t *)FixupContent; 333 if ((Instr & 0xffffffe0) != 0x90000000) 334 return make_error<JITLinkError>("PAGE21/GOTPAGE21 target is not an " 335 "ADRP instruction with a zero " 336 "addend"); 337 break; 338 } 339 case PageOffset12: { 340 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 341 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 342 else 343 return TargetSymbolOrErr.takeError(); 344 uint32_t Instr = *(const ulittle32_t *)FixupContent; 345 uint32_t EncodedAddend = (Instr & 0x003FFC00) >> 10; 346 if (EncodedAddend != 0) 347 return make_error<JITLinkError>("GOTPAGEOFF12 target has non-zero " 348 "encoded addend"); 349 break; 350 } 351 case GOTPageOffset12: { 352 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 353 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 354 else 355 return TargetSymbolOrErr.takeError(); 356 uint32_t Instr = *(const ulittle32_t *)FixupContent; 357 if ((Instr & 0xfffffc00) != 0xf9400000) 358 return make_error<JITLinkError>("GOTPAGEOFF12 target is not an LDR " 359 "immediate instruction with a zero " 360 "addend"); 361 break; 362 } 363 case PointerToGOT: 364 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 365 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 366 else 367 return TargetSymbolOrErr.takeError(); 368 break; 369 case Delta32: 370 case Delta64: { 371 // We use Delta32/Delta64 to represent SUBTRACTOR relocations. 372 // parsePairRelocation handles the paired reloc, and returns the 373 // edge kind to be used (either Delta32/Delta64, or 374 // NegDelta32/NegDelta64, depending on the direction of the 375 // subtraction) along with the addend. 376 auto PairInfo = 377 parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress, 378 FixupContent, ++RelItr, RelEnd); 379 if (!PairInfo) 380 return PairInfo.takeError(); 381 std::tie(*Kind, TargetSymbol, Addend) = *PairInfo; 382 assert(TargetSymbol && "No target symbol from parsePairRelocation?"); 383 break; 384 } 385 default: 386 llvm_unreachable("Special relocation kind should not appear in " 387 "mach-o file"); 388 } 389 390 LLVM_DEBUG({ 391 dbgs() << " "; 392 Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol, 393 Addend); 394 printEdge(dbgs(), *BlockToFix, GE, 395 getMachOARM64RelocationKindName(*Kind)); 396 dbgs() << "\n"; 397 }); 398 BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(), 399 *TargetSymbol, Addend); 400 } 401 } 402 return Error::success(); 403 } 404 405 unsigned NumSymbols = 0; 406 }; 407 408 class PerGraphGOTAndPLTStubsBuilder_MachO_arm64 409 : public PerGraphGOTAndPLTStubsBuilder< 410 PerGraphGOTAndPLTStubsBuilder_MachO_arm64> { 411 public: 412 using PerGraphGOTAndPLTStubsBuilder< 413 PerGraphGOTAndPLTStubsBuilder_MachO_arm64>::PerGraphGOTAndPLTStubsBuilder; 414 415 bool isGOTEdgeToFix(Edge &E) const { 416 return (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 || 417 E.getKind() == PointerToGOT) && 418 E.getTarget().isExternal(); 419 } 420 421 Symbol &createGOTEntry(Symbol &Target) { 422 auto &GOTEntryBlock = G.createContentBlock( 423 getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0); 424 GOTEntryBlock.addEdge(Pointer64, 0, Target, 0); 425 return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false); 426 } 427 428 void fixGOTEdge(Edge &E, Symbol &GOTEntry) { 429 if (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12) { 430 // Update the target, but leave the edge addend as-is. 431 E.setTarget(GOTEntry); 432 } else if (E.getKind() == PointerToGOT) { 433 E.setTarget(GOTEntry); 434 E.setKind(Delta32); 435 } else 436 llvm_unreachable("Not a GOT edge?"); 437 } 438 439 bool isExternalBranchEdge(Edge &E) { 440 return E.getKind() == Branch26 && !E.getTarget().isDefined(); 441 } 442 443 Symbol &createPLTStub(Symbol &Target) { 444 auto &StubContentBlock = 445 G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0); 446 // Re-use GOT entries for stub targets. 447 auto &GOTEntrySymbol = getGOTEntry(Target); 448 StubContentBlock.addEdge(LDRLiteral19, 0, GOTEntrySymbol, 0); 449 return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false); 450 } 451 452 void fixPLTEdge(Edge &E, Symbol &Stub) { 453 assert(E.getKind() == Branch26 && "Not a Branch32 edge?"); 454 assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?"); 455 E.setTarget(Stub); 456 } 457 458 private: 459 Section &getGOTSection() { 460 if (!GOTSection) 461 GOTSection = &G.createSection("$__GOT", sys::Memory::MF_READ); 462 return *GOTSection; 463 } 464 465 Section &getStubsSection() { 466 if (!StubsSection) { 467 auto StubsProt = static_cast<sys::Memory::ProtectionFlags>( 468 sys::Memory::MF_READ | sys::Memory::MF_EXEC); 469 StubsSection = &G.createSection("$__STUBS", StubsProt); 470 } 471 return *StubsSection; 472 } 473 474 ArrayRef<char> getGOTEntryBlockContent() { 475 return {reinterpret_cast<const char *>(NullGOTEntryContent), 476 sizeof(NullGOTEntryContent)}; 477 } 478 479 ArrayRef<char> getStubBlockContent() { 480 return {reinterpret_cast<const char *>(StubContent), sizeof(StubContent)}; 481 } 482 483 static const uint8_t NullGOTEntryContent[8]; 484 static const uint8_t StubContent[8]; 485 Section *GOTSection = nullptr; 486 Section *StubsSection = nullptr; 487 }; 488 489 const uint8_t 490 PerGraphGOTAndPLTStubsBuilder_MachO_arm64::NullGOTEntryContent[8] = { 491 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 492 const uint8_t PerGraphGOTAndPLTStubsBuilder_MachO_arm64::StubContent[8] = { 493 0x10, 0x00, 0x00, 0x58, // LDR x16, <literal> 494 0x00, 0x02, 0x1f, 0xd6 // BR x16 495 }; 496 497 } // namespace 498 499 namespace llvm { 500 namespace jitlink { 501 502 class MachOJITLinker_arm64 : public JITLinker<MachOJITLinker_arm64> { 503 friend class JITLinker<MachOJITLinker_arm64>; 504 505 public: 506 MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx, 507 std::unique_ptr<LinkGraph> G, 508 PassConfiguration PassConfig) 509 : JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {} 510 511 private: 512 513 static unsigned getPageOffset12Shift(uint32_t Instr) { 514 constexpr uint32_t LoadStoreImm12Mask = 0x3b000000; 515 constexpr uint32_t Vec128Mask = 0x04800000; 516 517 if ((Instr & LoadStoreImm12Mask) == 0x39000000) { 518 uint32_t ImplicitShift = Instr >> 30; 519 if (ImplicitShift == 0) 520 if ((Instr & Vec128Mask) == Vec128Mask) 521 ImplicitShift = 4; 522 523 return ImplicitShift; 524 } 525 526 return 0; 527 } 528 529 Error applyFixup(LinkGraph &G, Block &B, const Edge &E, 530 char *BlockWorkingMem) const { 531 using namespace support; 532 533 char *FixupPtr = BlockWorkingMem + E.getOffset(); 534 JITTargetAddress FixupAddress = B.getAddress() + E.getOffset(); 535 536 switch (E.getKind()) { 537 case Branch26: { 538 assert((FixupAddress & 0x3) == 0 && "Branch-inst is not 32-bit aligned"); 539 540 int64_t Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 541 542 if (static_cast<uint64_t>(Value) & 0x3) 543 return make_error<JITLinkError>("Branch26 target is not 32-bit " 544 "aligned"); 545 546 if (Value < -(1 << 27) || Value > ((1 << 27) - 1)) 547 return makeTargetOutOfRangeError(G, B, E); 548 549 uint32_t RawInstr = *(little32_t *)FixupPtr; 550 assert((RawInstr & 0x7fffffff) == 0x14000000 && 551 "RawInstr isn't a B or BR immediate instruction"); 552 uint32_t Imm = (static_cast<uint32_t>(Value) & ((1 << 28) - 1)) >> 2; 553 uint32_t FixedInstr = RawInstr | Imm; 554 *(little32_t *)FixupPtr = FixedInstr; 555 break; 556 } 557 case Pointer32: { 558 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 559 if (Value > std::numeric_limits<uint32_t>::max()) 560 return makeTargetOutOfRangeError(G, B, E); 561 *(ulittle32_t *)FixupPtr = Value; 562 break; 563 } 564 case Pointer64: 565 case Pointer64Anon: { 566 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 567 *(ulittle64_t *)FixupPtr = Value; 568 break; 569 } 570 case Page21: 571 case GOTPage21: { 572 assert((E.getKind() != GOTPage21 || E.getAddend() == 0) && 573 "GOTPAGE21 with non-zero addend"); 574 uint64_t TargetPage = 575 (E.getTarget().getAddress() + E.getAddend()) & 576 ~static_cast<uint64_t>(4096 - 1); 577 uint64_t PCPage = FixupAddress & ~static_cast<uint64_t>(4096 - 1); 578 579 int64_t PageDelta = TargetPage - PCPage; 580 if (PageDelta < -(1 << 30) || PageDelta > ((1 << 30) - 1)) 581 return makeTargetOutOfRangeError(G, B, E); 582 583 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 584 assert((RawInstr & 0xffffffe0) == 0x90000000 && 585 "RawInstr isn't an ADRP instruction"); 586 uint32_t ImmLo = (static_cast<uint64_t>(PageDelta) >> 12) & 0x3; 587 uint32_t ImmHi = (static_cast<uint64_t>(PageDelta) >> 14) & 0x7ffff; 588 uint32_t FixedInstr = RawInstr | (ImmLo << 29) | (ImmHi << 5); 589 *(ulittle32_t *)FixupPtr = FixedInstr; 590 break; 591 } 592 case PageOffset12: { 593 uint64_t TargetOffset = 594 (E.getTarget().getAddress() + E.getAddend()) & 0xfff; 595 596 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 597 unsigned ImmShift = getPageOffset12Shift(RawInstr); 598 599 if (TargetOffset & ((1 << ImmShift) - 1)) 600 return make_error<JITLinkError>("PAGEOFF12 target is not aligned"); 601 602 uint32_t EncodedImm = (TargetOffset >> ImmShift) << 10; 603 uint32_t FixedInstr = RawInstr | EncodedImm; 604 *(ulittle32_t *)FixupPtr = FixedInstr; 605 break; 606 } 607 case GOTPageOffset12: { 608 assert(E.getAddend() == 0 && "GOTPAGEOF12 with non-zero addend"); 609 610 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 611 assert((RawInstr & 0xfffffc00) == 0xf9400000 && 612 "RawInstr isn't a 64-bit LDR immediate"); 613 614 uint32_t TargetOffset = E.getTarget().getAddress() & 0xfff; 615 assert((TargetOffset & 0x7) == 0 && "GOT entry is not 8-byte aligned"); 616 uint32_t EncodedImm = (TargetOffset >> 3) << 10; 617 uint32_t FixedInstr = RawInstr | EncodedImm; 618 *(ulittle32_t *)FixupPtr = FixedInstr; 619 break; 620 } 621 case LDRLiteral19: { 622 assert((FixupAddress & 0x3) == 0 && "LDR is not 32-bit aligned"); 623 assert(E.getAddend() == 0 && "LDRLiteral19 with non-zero addend"); 624 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 625 assert(RawInstr == 0x58000010 && "RawInstr isn't a 64-bit LDR literal"); 626 int64_t Delta = E.getTarget().getAddress() - FixupAddress; 627 if (Delta & 0x3) 628 return make_error<JITLinkError>("LDR literal target is not 32-bit " 629 "aligned"); 630 if (Delta < -(1 << 20) || Delta > ((1 << 20) - 1)) 631 return makeTargetOutOfRangeError(G, B, E); 632 633 uint32_t EncodedImm = (static_cast<uint32_t>(Delta) >> 2) << 5; 634 uint32_t FixedInstr = RawInstr | EncodedImm; 635 *(ulittle32_t *)FixupPtr = FixedInstr; 636 break; 637 } 638 case Delta32: 639 case Delta64: 640 case NegDelta32: 641 case NegDelta64: { 642 int64_t Value; 643 if (E.getKind() == Delta32 || E.getKind() == Delta64) 644 Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 645 else 646 Value = FixupAddress - E.getTarget().getAddress() + E.getAddend(); 647 648 if (E.getKind() == Delta32 || E.getKind() == NegDelta32) { 649 if (Value < std::numeric_limits<int32_t>::min() || 650 Value > std::numeric_limits<int32_t>::max()) 651 return makeTargetOutOfRangeError(G, B, E); 652 *(little32_t *)FixupPtr = Value; 653 } else 654 *(little64_t *)FixupPtr = Value; 655 break; 656 } 657 default: 658 llvm_unreachable("Unrecognized edge kind"); 659 } 660 661 return Error::success(); 662 } 663 664 uint64_t NullValue = 0; 665 }; 666 667 Expected<std::unique_ptr<LinkGraph>> 668 createLinkGraphFromMachOObject_arm64(MemoryBufferRef ObjectBuffer) { 669 auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjectBuffer); 670 if (!MachOObj) 671 return MachOObj.takeError(); 672 return MachOLinkGraphBuilder_arm64(**MachOObj).buildGraph(); 673 } 674 675 void link_MachO_arm64(std::unique_ptr<LinkGraph> G, 676 std::unique_ptr<JITLinkContext> Ctx) { 677 678 PassConfiguration Config; 679 680 if (Ctx->shouldAddDefaultTargetPasses(G->getTargetTriple())) { 681 // Add a mark-live pass. 682 if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple())) 683 Config.PrePrunePasses.push_back(std::move(MarkLive)); 684 else 685 Config.PrePrunePasses.push_back(markAllSymbolsLive); 686 687 // Add an in-place GOT/Stubs pass. 688 Config.PostPrunePasses.push_back( 689 PerGraphGOTAndPLTStubsBuilder_MachO_arm64::asPass); 690 } 691 692 if (auto Err = Ctx->modifyPassConfig(*G, Config)) 693 return Ctx->notifyFailed(std::move(Err)); 694 695 // Construct a JITLinker and run the link function. 696 MachOJITLinker_arm64::link(std::move(Ctx), std::move(G), std::move(Config)); 697 } 698 699 const char *getMachOARM64RelocationKindName(Edge::Kind R) { 700 switch (R) { 701 case Branch26: 702 return "Branch26"; 703 case Pointer64: 704 return "Pointer64"; 705 case Pointer64Anon: 706 return "Pointer64Anon"; 707 case Page21: 708 return "Page21"; 709 case PageOffset12: 710 return "PageOffset12"; 711 case GOTPage21: 712 return "GOTPage21"; 713 case GOTPageOffset12: 714 return "GOTPageOffset12"; 715 case PointerToGOT: 716 return "PointerToGOT"; 717 case PairedAddend: 718 return "PairedAddend"; 719 case LDRLiteral19: 720 return "LDRLiteral19"; 721 case Delta32: 722 return "Delta32"; 723 case Delta64: 724 return "Delta64"; 725 case NegDelta32: 726 return "NegDelta32"; 727 case NegDelta64: 728 return "NegDelta64"; 729 default: 730 return getGenericEdgeKindName(static_cast<Edge::Kind>(R)); 731 } 732 } 733 734 } // end namespace jitlink 735 } // end namespace llvm 736
Indexes created Wed Jun 10 00:26:05 UTC 2026